In the past, in automobiles (an electric car and a hybrid car in particular), devices such as a motor, a battery, and an inverter are connected to each other by a shield electric wire, and a shield connector structure has been suggested to ground connect the case of the device and the shield electric wire (see, for example, Patent Literature 1). A shield connector structure 100 described in Patent Literature 1 is configured to connect a metal case 6 of a connection target object and a shield electric wire 1 as shown in FIG. 7, and to make the connection portion waterproof. The shield electric wire 1 is a coaxial cable including a conductive body 2, an internal insulating covering 3 covering the periphery of the conductive body 2, a shield unit 4 made of a conductive body such as a braided wire provided on the periphery of the internal insulating covering 3, and an external insulating covering 5 covering the periphery of the shield unit 4. The metal case 6 is provided with an insertion hole 7 into which the shield electric wire 1 is inserted, and a bolt hole 8 into which a bolt 106 for fixing a connection member 101 is screwed.
This shield connector structure 100 includes a housing 101 allowing the shield electric wire 1 to be inserted therethrough and fixed to the metal case 6, a shield member 102 electrically connecting the metal case 6 and the shield unit 4 of the shield electric wire 1, a first seal member 103 interposed between the inner surface of the shield member 102 and the outer surface of the external insulating covering 5 of the shield electric wire 1, a second seal member 104 interposed between the outer surface of the shield member 102 and the inner surface of the insertion hole 7 of the metal case 6, a shield pipe 105 swaged and covering the shield unit 4 connected to the shield member 102, a bolt 106 for fixing the connection member 101 with the metal case 6, and a corrugated tube 107 which is an exterior member covering the shield electric wire 1 at the outside of the metal case 6.
The housing 101 is fixed to one side of the metal case 6 (external side), and is configured to hold the shield member 102 in such a manner that the shield member 102 is sandwiched between the housing 101 and the metal case 6, and includes an insertion unit 111 in which the shield electric wire 1 is inserted, a tubular protrusion unit 112 extending to the other side (inside) of the metal case 6 with respect to the insertion unit 111 and entering into the insertion hole 7, and a flange unit 113 extending to the outside in the diameter direction of the insertion unit 111 and fixed to the metal case 6. The shield member 102 includes a first tubular unit 121, a second tubular unit 122, and a third tubular unit 123, of which diameters increase in three stages from the other end to the one end side of the metal case 6, and includes a flanged portion 124 bent continuously to the third tubular unit 123 and along one surface (outer surface) of the metal case 6.
The shield unit 4 of the shield electric wire 1 is connected to the first tubular unit 121 by removing the external insulating covering 5 at the other side of the metal case 6 to be exposed, bending it to be overlaid on the first tubular unit 121 of the shield member 102, swaging the shield pipe 105 from the outside of the shield unit 4. As described above, the shield unit 4 of the shield electric wire 1 is connected to the first tubular unit 121, and the flanged portion 124 of the shield member 102 is held by the housing 101 and the one side surface of the metal case 6, so that the shield unit 4 is ground connected to the metal case 6 via the shield member 102.
The first seal member 103 is formed in a tubular shape as a whole and made of an elastic material such as rubber, and has lip portion in a protruding and recessed shape and in an annular shape on the inner peripheral surface and the outer peripheral surface thereof, wherein multiple lip portions on the inner peripheral surface are brought into close contact with the outer surface of the external insulating covering 5 of the shield electric wire 1, and multiple lip portions on the outer peripheral surface are brought into close contact with each inner surface of the second tubular unit 122 of the shield member 102 and the tubular protrusion unit 112 of the housing 101, so that the space between the shield electric wire 1 and the shield member 102 and the connection member 101 is configured to be sealed. On the other hand the second seal member 104 is formed in a tubular shape as a whole and made of an elastic material such as rubber, and includes two lines of lip portions on each of the inner peripheral surface and the outer peripheral surface, wherein the lip portions on the inner peripheral surface are brought into close contact with the outer surface of the second tubular unit 122 of the shield member 102, and the lip portions of the outer peripheral surface are brought into close contact with the inner surface of the insertion hole 7 of the metal case 6, so that the space between the shield member 102 and the metal case 6 is configured to be sealed.
As described above, in the conventional shield connector structure 100 described in Patent Literature 1, the shield electric wire 1 is mechanically connected to the metal case 6 by the housing 101, and the shield unit 4 is electrically connected via the shield member 102 to the metal case 6. Further, sealing is provided by the first seal member 103 and the second seal member 104, so that water-stop is provided in the connection portion of the shield electric wire 1 and the metal case 6, and this can prevent water and the like from entering from the outside to the inside of the metal case 6.